U.S. Pat. No. 6,027,826 to de Rochemont, et al. discloses articles and methods to form oxide ceramic on metal substrates to form laminate, filament and wire metal-ceramic composite structures using liquid aerosol spray techniques. U.S. Pat. Nos. 6,323,549 and 6,742,249 to de Rochemont, et al. disclose articles that comprise, and methods to construct, an interconnect structure that electrically contacts a semiconductor chip to a larger system using at least one discrete wire that is embedded in amorphous silica ceramic, as well as methods to embed passive components within said interconnect structure. U.S. Pat. Nos. 5,707,715 and 6,143,432 to de Rochemont, et al. (the '715 and '432 patents) disclose articles and methods to relieve thermally-induced mechanical stress in metal-ceramic circuit boards and metal-ceramic and ceramic-ceramic composite structures. U.S. Pat. No. 6,027,826 to de Rochemont, et al. disclose articles and methods to form oxide ceramic on metal substrates to form laminate, filament and wire metal-ceramic composite structures using liquid aerosol spray techniques. U.S. Pat. Nos. 6,323,549 and 6,742,249 to de Rochemont, et al. disclose articles that comprise, and methods to construct, an interconnect structure that electrically connects a semiconductor chip to a larger system using at least one discrete wire that is embedded in silica ceramic, as well as methods to embed passive components within said interconnect structure. U.S. patent application Ser. No. 11/479,159 (U.S. Pub. No. 2007/0003781) (hereinafter “de Rochemont '159”) discloses articles and methods that laminate passive components (resistors, capacitors, inductors) on an exposed or a buried microelectronic surface using liquid aerosol sprays or inkjet deposition systems. U.S. patent application Ser. No. 11/660,042 (Pub. No. 2007/0139976) (hereinafter “de Rochemont '042) discloses articles and methods that laminate passive components on an exposed surface layer or a buried microelectronic layer to form a power management device using laminated resistors, capacitors, inductors or transformers. U.S. Pat. No. 7,405,698 is used to miniaturize artificial magnetic conducting ground planes and form meta-material dielectrics that, in combination with de Rochemont '159, enable electrically small antennas. The contents of each of these references are incorporated herein by reference as if laid out in their entirety.
RFID systems allow an object to be remotely identified by a radio frequency “interrogator” signal, which activates a “chirp” or “read” signal from the RFID tag. Passive RFID systems do not have any internal power sources (such as battery elements) within the tag to avoid maintenance needs and, consequently, will have read ranges—(the distance from which the tag can be remotely identified)—limited to 65 to 100 feet. This is the case because the interrogator signal must activate and power the “read signal” from the RFID transponder. Therefore, the interrogator signal must be powerful to simultaneously overcome signal path losses between the read head and the RFID tag, to activate the “read” signal, and still be detectable by the remote read head. State-of-the-art passive RFID systems that incorporate surface-acoustic wave systems will require power levels of −15 dB to −18 dB simply to activate the chirped read signal.
RFID systems are used to manage assets in inventory and during transport. Recently, piracy and theft during logistical transport has developed a need for passive RFID sensors that can not only report asset location, but additional information that might indicate whether or not the asset has been compromised or tampered to a surveillance vehicle located several miles away from the asset, such as an unmanned aerial vehicle.
Therefore, methods that enable passive RFID sensors to remotely report the location or tampering of an asset at distances up to and exceeding a distance of 10 miles is desirable. It is also desirable that such an RFID system have a planar structure so that it may be concealed in the wall of a container to protect it from being detected, damaged or destroyed prior to or during the time an asset is tampered.